Engineering a self-eliminating transgene in the yellow fever mosquito, .

Promising genetics-based approaches are being developed to reduce or prevent the transmission of mosquito-vectored diseases. Less clear is how such transgenes can be removed from the environment, a concern that is particularly relevant for highly invasive gene drive transgenes. Here, we lay the groundwork for a transgene removal system based on single-strand annealing (SSA), a eukaryotic DNA repair mechanism. An SSA-based rescuer strain ( ) was engineered to have direct repeat sequences (DRs) in the () gene flanking the intervening transgenic cargo genes, and . Targeted induction of DNA double-strand breaks (DSBs) in the transgene successfully triggered complete elimination of the entire cargo from the strain, restoring the wild-type gene, and thereby, normal eye pigmentation. Our work establishes the framework for strategies to remove transgene sequences during the evaluation and testing of modified strains for genetics-based mosquito control.